One of my favourite parts of the reception is the speeches. I love hearing the funny stories and the sharing of touching moments. Most people who give a speech are well prepared or at minimum have written out notes. The problems happen when someone decides to "wing it". Those speeches rarely go well.
It's not that the individual says anything inappropriate. That doesn't happen very often. It's that they don't know when to stop talking and they just keep rambling on long after people have lost interest. There's an old show biz saying, "always leave them wanting more". The same thing applies to wedding speeches.
If possible, encourage everyone who will be giving a speech to write out what they want to say. That includes the list of "thank you's" from the bride and groom. You don't want anyone being handed a mic and given free reign to talk as long as they want about whatever comes in to their head.
By all means, fill your reception with speeches from all your loved ones. Those moments are a very important part of the day. You will treasure what is shared (make sure you get it on video!) and be touched by the love and care that is shown toward you. However, having each presenter use prepared notes will make things run much more smoothly and limit the number of times you bury your head in your hands and wish the sound man would cut the power.